Regulating-transformer.



PATENTED JAN. 2, 1906. H. J. BLAKBSLEE. REGULATING TRANSFORMER.APPLICATION FILED APR 8 1905 2 SHEETS-SHEET 1.

PATENTED JAN. 2, 1906.

H. J. BLAKESLEE.

REGULATING TRANSFORMER.

APPLICATION FILED APILB, 1905.

2 SHEETSSHEET 2.

tion.

HENRY J. BLAKESLEE, OF HARTFORD, CONNECTICUT.

REGULATlNG-TRANSFORMER.

Specification of Letters Patent.

Patented Jan. 2, 1906.

Application filed ipril 8, 1905. Serial No. 254,479-

To all whom it may concern:

Be it known that I, HENRY J. BLAKESLEE, a citizen of the United States,residing at Hartford, in the county of Hartford and State ofConnecticut, have invented a new and useful Regulating-Transformer, ofwhich the following is a specification.

This invention relates to an alternatingcurrent transformer which isdesigned to regulate the current or electromotive force in circuits inwhich it is connected or which it supplies.

The object of the invention is to provide a simple transformer of thisclass having a magnetic circuit of constant and low reluctance andwithout moving conductors or sliding contacts.

Alternating-current regulators which opcrate on the transformerprinciple, as previously built have either a movable primary coil andstationary secondary coil, or a movable secondary coil and stationaryprimary coil, or have both primary and secondary coils movable, amovable coil upon a mag netic core, either with or without stationarycoils in series therewith, stationary, primary, and secondary coils witha movable core so arranged that the reluctance of the magnetic circuitis variable, a coil with a core of variable magnetic reluctance, meansfor cut ting in or out turnsof a coil upon a magnetic core, means forcutting in or out turns of a primary coil or of a secondary coil, orvarious combinations of these several features.

.An alternating current regulating transformer which embodies myinvention has only stationary coils and a magnetic circuit of constantreluctance so arranged that the total magnetic flux is at all timesinclosed by one coil, while from the minimum to the maximum magneticflux is inclosed by the other coil automatically or at will, accordingto the required conditions.

Figure 1 of the accompanying drawings shows a central longitudinalsection of a regulating-transformer that embodies this inven- Fig. 2shows an end view with one of the heads omitted. Fig. 3 shows atransverse section through the middle. Fig. 4 shows a centrallongitudinal section with the core omitted. Fig. 5 shows a centrallongitudinal section of a transformer of modified construction. Fig. 6shows an end view of this modified form without the head. Fig. 7

- shows a transverse section through the mid dle of this latter form.Fig. 8 shows a central longitudinal section of the modified form withthe core omitted. Fig. 9 shows one head and a counterbalance that may beemployed. Fig. 10 is a diagram illustrating various ways the primary andsecondary coils may be arranged.

The frame of the transformer is built up of thin sheets of magneticmetal in a common manner. This laminated frame, which is preferablycylindrical, is held together by any suitable means and at each end hasa non-magnetic head 2. The primary coil 3, which is connected with themains in the usual way, is located in an annular recess in the middle ofthe frame, so as to encircle the core 4. The secondary coil 5, which maybe connected with branch wires leading to lamps, motors, or heaters orto feed-wires, as usual, is wound upon polar projections 6, that extendinwardly from each side of the mid dle of the cylindrical frame. Theremay be any desired number of polar projections, and the secondary coilmay be wound upon or looped about these in many ways. In the form of theinvention that is first illustrated there are four polar projections ateach end and the secondary coil encircles these polar projections, sothat an edge of one loop overlaps an edge of the adjacent loop. In thisform the adjacent loops of the secondary coil are wound oppositely. Inthe second form illustrated the secondary coil passes back and forththrough the spaces between the polar projections and alternately on theinside and on the outside of the polar projections.

The core, which extends the length of the frame, is built up of ironsheets and is mounted on an arbor 7, that is supported by the heads. Thetwo outer edges of the core are curved and conform closely to the innerwall of the frame and the insides of the coils, while the two flat sidesare some distance from the inner wall of the frame and the coils. Thespaces between the sides of the core and the coils may be left vacant,as shown in Fig. 3, or non-magnetic conductors 8 may be attached to thesides of the core, as shown in Fig. 7, for the purpose of decreasing theimpedance of the loops opposite which they may happen to be. The arbormay be provided with any common means for counterbalancing the magnetictorque of the core. In the form shown this counterbalance is a pulley 9,around which passes a cord 10, to which a weight 1 1 is fastened.

In this transformer the stationary primary IIC coil always has the samerelation to the frame and the core always has the same relation to theframe and the primary coil which encircles it. Consequently the magneticreluctance will be constant.

In the form of the invention illustrated in Figs. 5 to 8 when the corestands in the position shown the maximum number of lines of force fluxthrough the secondary coil, inducing therein a maximum electromotiveforce. If the core occupies a position ninety degrees from that shown inthe drawings, the secondary would inclose a minimum number of lines offorce and the electromotive force induced therein would be the minimum.The pull of the counterbalance always tends to bring the core to theposition shown in the drawings, and the torque, due to the current inthe secondary, tends to bring the core to a position ninety degrees fromthat shown. There fore the core being provided with a properly designedand adjusted counterbalance it is evident that the secondary coil can bemade to deliver approximately a constant current to a circuit ofwidely-varying impedance.

If the secondary coil is arranged as illustrated in Figs. 1 to 4: andthe adjacent loops are wound and connected so that their electromotiveforces oppose each other, it is evident that with the core in theposition shown a maximum electromotive force will be induced in theloops nearest the edges of the core and a minimum electromotive force inthe loops farthest from the edges of the core, and when the core is in aposition at right angles to that shown a maximum electromotive forcewill be induced in the loops nearest the edges of the core and a minimumelectromotive force in the loops farthest from the edges of the core. Inthis case, however, the direction of the current would be in-onedirection when the core is in the position shown and would be in thereverse direction when the core was at right angles to that position.When the core is in a position at forty-five degrees from that shown,the resulting electromotive force from the adjacent loops near the edgesof the core, which are wound reversely and connected in series, would bezero. Therefore by connecting two such coils in series opposed andconnecting them in series with the feeder it is evident that theelectromotive force of the feeder may be either raised above or loweredbelow the electromotive force of the supply by changing the position ofthe core, the primary coil being connected to the supply in the usualmanner.

A transformer embodying this invention may be used in connection with aconstantpotential circuit for regulating a secondary circuit containinglamps or other electrical appliances connected in series, in which casethe primary and secondary coils can be arranged as indicated at a inFig. 10 or may be used for raising or lowering the electromotive forceof a feedercircuit, in which case the primary coil can be connected inmultiple and the secondary coil in series with the load, as indicated atb in Fig. 10, or may be used as a choke-coil for lamps or otherappliances connected in series with a constant current-feeder system, inwhich case the coils could be connected in series with each other andthe load, as indicated at c in Fig. 10. There are other uses to which.one of these transformers could be putsuch as for starting, stopping,reversing, and regulating the speed of an alternating current motorwhichuses will be readily understood by an electrician, so will not be hereinspecified in detail. The number of polar projections or the number andarrangement of coils and the means for counterbalancing the torque ofthe core are immaterial and may be varied with out departing from theinvention, and, if desired, the core may be moved by hand instead ofautomatically forproducing the desired effect.

The invention claimed is- 1. A regulating-transformer, having acylindrical magnetic frame, a stationary primary coil, a stationarysecondary coil, and a core with its axis extending perpendicular to theplane of the primary coil and movable within the frame and the primaryand secondary coils, substantially as specified.

2. A regulating-transformer having a magnetic frame, polar projectionson the interior of the frame, a stationary primary coil in the interiorof the frame, a stationary secondary coil encircling polar projectionsfrom the in terior of the frame, and a magnetic core movable within theframe and the coils, substantially as specified.

3. A regulating-transformer having a magnetic frame, polar projectionson the interior of the frame, a stationary primary coil encircling theinterior of the frame, a stationary secondary coil encircling polarprojections from the interior of the frame, a magnetic core movablewithin the frame and the coils, and a counterbalance connected with thecore, substantially as specified.

4. Aregulating-transformer having a magnetic frame, a stationary primarycoil, a stationary secondary coil, and a core always having the samemagnetic relation to the primary coil but adapted to be moved to varyits magnetic relation with. the secondary coil, substantially asspecified.

5. A regulating-transformer having a stationary magnetic frame and amovable core, a fixed primary coil arranged to always oncircle the totalflux through the core, and a fixed secondary coil so arranged that theflux through it varies from maximum to minimum according to the positionof the core, substantially as specified.

6. A regulating-transformer having a cy- I lindrical magnetic frame,polar projections on the interior of the frame, an annular primary coilfixed in the interior of the frame, a fixed secondary coil embracingpolar proj ections from the interior of the frame, a core extendingthrough the frame Within the primary and secondary coils, and means forcounterbalancin the magnetic torque of the. core, substantia y asspecified.

7. A regulating-transformer having a cylindrical magnetic frame, polarprojections on the interior of the frame, a primary coil fixed in arecess in the middle of the frame, a secondary coil Wound in reversedirections about polar projections from the interior of the frame, and amagnetic core extending through the frame and the primary and stationarycoils, substantially as specified.

8. A regulating-transformer having a stationary magnetic frame, a fixedprimary coil encircling the interior of the frame, a fixed secondarycoil in the interior of the frame, and a magnetic core movable Withinthe frame and the primary coil, the axis of the core extendingperpendicular to the plane of the primary coil, and the said coils beingarranged so that the primary always encircles the total flux through thecore While the secondary varies from maximum to minimum according to theposition .of the core, substantially as specified.

9. A regulating-transformer having a stationary magnetic frame, a fixedprimary coil encircling the interior of the frame, a fixed secondarycoil in the interior of the frame, a magnetic core Within the frame andthe primary coil, the axis of the core extending perpendicular to theplane of the primary coil, and non-magnetic conductors attached to thecore in such manner as to lie opposite inactive sections of the magneticframe, substantially as specified.

10. A regulating-transformer having a stationary magnetic frame, a fixedprimary coil encircling the interior of the frame, a fixed secondarycoil in the interior of the frame, a magnetic core Within the frame andthe primary coil, the axis of the core extending perpendicular to theplane of the primary coil, and a counterbalance connected with andtending to rotate the core on its axis in a direction opposite to themagnetic torque, substantially as specified.

HENRY J. BLAKESLEE.

Witnesses H. R. l/VILLIAMs. E. M. LOWE.

